Physiological studies of swallowing and the diagnosis and treatment of dysphagia are crucially dependent of detailed information of respiratory and feeding events. Home telemonitoring is of great interest in this area, where large numbers of people have long term conditions. The purpose of this study was twofold: (1) describe a new configurable instrument that can be used in ambulatory and telemedicine applications and (2) evaluate the performance of this device in the description of physiological and abnormal events during water swallowing. The instrument is able to detect when water is beginning to enter the mouth of the volunteer, to unobtrusively monitor the respiration, and to characterize the elevation of the larynx. The performance of the system was tested in normal subjects and patients with dysphagia, showing results in close agreement with the physiology. We concluded that the developed system could be a useful tool for the ambulatory evaluation of respiratory and feeding events and for the implementation of telemedicine services, contributing to reduce the costs of the assistance offered to patients with dysphagia.

Disordered swallowing, or dysphagia, is a common problem seen in patients undergoing treatment for cancer, stroke and neurodegenerative illnesses. This disease is associated with aspiration-induced chest infections. The methods currently used for diagnosis, however, are qualitative or based on expensive equipment. Swallowing accelerometry is a promising low-cost, quantitative and noninvasive tool for the evaluation of swallowing. This work describes the design and application of a bedside instrument able to evaluate swallowing mechanisms and to identify patients at risk of aspiration. Three-axis swallowing accelerometry was used to measure the neck vibrations associated with deglutition, providing analog signals to a virtual instrument developed in LabVIEW environment. In vivo tests in normal subjects as well as tests with disphagic patients showed that the system was able to easily and non-invasively detect changes in the swallowing acceleration pattern associated with increasing values of water volume (p < 0.02) and disphagia. We concluded that the developed system could be a useful tool for the objective bedside evaluation of patients at risk of aspiration.

This article aims to characterize the mechanical behavior of the Acapella Blue, a respiratory rehabilitation device designed to aid sputum clearance. In this scope, the present study initially describes in detail the peak-to-peak oscillation amplitude (App) and peak frequency (fp) behavior, as well as positive pressure level (Ppl), in the flow range more comonly found in practice. The parameters were evaluated in all 5 adjustment levels of the equipment in intervals of 50 mL/s. The device characterization has shown fp up to 23 Hz, App from 0.2 to 2.8 cmH(2)O and Ppl ranging from 1.2 to 13.5 cmH(2)O. The studied device may produce oscillation in the ranges of ciliary movements and respiratory system resonance frequency of patients with respiratory diseases. Data obtained in this work may help to optimize the use of the Acapella Blue device in respiratory rehabilitation. Suggestions for the practical use of the device are also presented.

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The aim of this work is to describe a new instrument based on the negative expiratory pressure technique able to detect expiratory flow limitation (EFL) in patients with respiratory diseases. First, we describe the design details of a virtual instrument able to apply a low pressure at the mouth during tidal expiration, simultaneously measure flow and pressure, and automatically elaborate flow-volume curves. Then, the system accuracy is evaluated investigating normal subjects and patients with chronic obstructive pulmonary disease (COPD). These experimental results revealed higher (p〈0.001) EFL in COPD patients (58.5±19.9%) than in normal volunteers (1.5±2.5%). These results are in close agreement with the physiology, confirming the high scientific and clinical potential of this system.